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STABILIZING AND OHIENTING APPARATUS Original Filed Jan. lO, 1934 16 Sheets-Sheet 16 N6 Ew TTORNEYS i Patented `luly 1.6, 1940 U.NITED STATES PATENT OFFICE STABILIZING AND ORIENTING APPARATUS Johann Maria Boykow, deceased, late of Berlin- Lichterfelde, Germany, by Bianca Boykow,

Erika Boykow, and Johann Maria Boykow, Bad Wiessee, Bavaria, Germany, sole heirs, assignors to Deutsche Luftfahrt-und Handels- Aktiengesellschaft, Berlin, Germany, a corporation of Germany Original application January 10, 1934, Serial No.

705,997, now Patent No. 2,109,283, dated February 22, 1938. Divided and this application January 22, 1938, Serial No. 186,360

32 Claims.

'Ihis invention relates to a stabilized structure for navigational instruments, the present application being a division of an application led in the United States Patent Oflice by the vices for neutralizing friction.

Further objects and details of the invention will be apparent from the description following the effect of bearing 5 said Johann Maria Boykow, deceased, which aphereinafter and from the annexed drawings il- 5 plicaticn matured into Patent No. 2,109,283, Febiustrating an embodiment f the invention by ruary 22, 1938. Way of example.

Many instruments for indicating navigational In the said drawings Fig. 1 is a diagrammatic factors, as for instance the instrument disclosed VieW Showing the co-operative groups of appa- 10 in the aforementioned parent application, reratus and their main connections; Fig. 2 is a l0 quire that either the entire instrument or at least diagrammatic top View of the platform With the parts thereof should not partake in the oscillating apparatus mounted thereon, the protective cover movements of the craft equipped with such inbeing partly removed; Fig. 3 is a Side View therestrument. The main object of the present inof Fig. 4 is a side VieW of one of the stabilizing l5 vention is to provide a platform which is horigyros, Dart of the Casing and of the gyro float 15 zgntalhrtavbiiized and which may be orientated being in section; Fig. 5 is a vertical section of with respect to a certain earth di'bttumsl'h the upper Part 0f Fig 4 0n a larger Scale, along platform to be serviceable as a carrier for instruline 5-5 of Fig- 5, looking in the direction of ments requiring a stabilized and directed base. the arrow; Fig. 6 is a section along line 6--6 of 2O A further object of the invention is to provide Fig- 5; Figs- 7 and 8 are Sections similar t0 Figs- 20 a stabilized platform for an integrator, and 5 and 6 and siiOW the Corresponding Parts 0f the more particularly for integrators of the type other StabiliZing gyro; Fig. 9 is a vertical section claimed in said parent application, which serve 0f the compass syro arrangement; Figs. 10 and for ending the speed and distance traveled from 10a are derent views 0f parts thereof Fig. 11

accelerations of the craft equipped with the inteis a diagrammatic Side View of the azimuth gyro; 25 grators, and to use the movements of the inte- Fig. 12 is a section along line |2-l2 of Fig. 13, grators for correcting the working of the plat- Showing a transmitter rotating device for corf0rmstabi1izing meting rections according to the true earth rotation;

A further object of the invention is to provide Fig 13 is a section along line 13-13 of Fig. 12;

means whereby gyros mounted on the platform Fig. 14 is a vertical section of an integrator with 30 and serving as stabilizing and directing means the associated Darts; Fig- 15 is a top View of a will be safeguarded against incorrect operation Set of motors and transmitters; Fig- 16 is a Side due to bearing friction and to certain external View. Partly in section1 of a Shaking device; Fig. influencen 17 is a side View of parts for controlling the 'I'he invention consists of a platform on which Shaking device; Figs. 18d and 18b are sections 35 are mounted gyros which exert a stabilizing inalong lines Ita-|811 and lob-|817 respectively iiuence to hold the platform horizontal, and of Fig. 17; Fig. 19 is a diagrammatic representaother gyros for keeping the platform in a desired tion of the shaking device; Fig. 20 is a section direction, of another shaking device; Fig. 21 is a top view 4 The invention further consists of means for of a device for performing certain corrections 40 bringing about certain influences interacting beat the stabilizing gyros and the compass gyro;

g tween the various gyros in order to correct their Fig. 22 is a section along line 22-22 of Fig. 21; working. Fig. 23 is a circuit diagram of group A of Fig. 1; The invention further consists of means for Fig. 24 is a circuit diagram of group B of Fig. 1;

correcting the working of such gyros with the Fig. 25 is a circuit diagram of group C of Fig. 1 45 help of the integrators. Fig. 26 is a circuit diagram of group E of Fig. 1; The invention further consists of a platform Fig. 27 is a circuit diagram of group F of Fig. 1, with two integrators, one of which responds to and Fig. 28 is a diagram showing the interconaccelerations in east-west direction, the other to nection of the several instruments.

accelerations in north-south direction, said plat- The apparatus consists of a plurality of indi- 50 form being gimbal-suspended and stabilized by vidual instruments and auxiliary apparatus two gyros, one for each of the integrators, said which will be treated hereinafter in individual platform being also provided with a compass groups. These groups of instruments may either gyro as well as with an azimuth gyro. be arranged all on a common base or platform, or

The invention further comprises shaking desuch of them as do not require a stabilized base 55 may be mounted separately at suitable points of the craft. In the latter case, they need only to be interconnected by electric wires.

Group A comprises the integrators and the gyros for stabilizing and directing the platform on which they are mounted.

Group B comprises the shaking devices for preventing the incorrect operation due to the bearing friction in the instruments of group A.

Group C comprises a device for making certain corrections according to the speed of the craft.

Group D comprises an instrument which may be connected to the apparatus according to the present invention but does not form part of the subject-matter claimed in the present application.

Group E comprises two transmitters with constant drive by two motors.

Group F comprises manually operated transmitters for making corrections according to the true earth rotation.

3- denotes a three-phase current lead which thus contains three wires, denotes a direct current line which consists of two conductors, and denotes a single-phase current line likewise consisting of two conductors. The current sources not represented here may be of any kind as long as they supply current of the character and strength required. Letters a to y signify groups of conductors of each of the aforementioned groups A to F, shown in Figs. 23 to 27.

The terms receivers and transmitters used below in the description and in the claims, are to be understood as referring to apparatus of the character frequently employed on board ship in the form of engine telegraphs in which a rotatable part of the transmitter causes a rotatable part of a receiver to rotate through the same angle. Such transmitters and receivers may have armatures with three-phase windings and fields with a one-phase Winding. An integrator in the sense of this invention is an instrument which is adapted to respond to accelerations of the craft in a predetermined direction, and to integrate such accelerations so as to rotate with a speed proportional to the speed of the craft in such direction. An integrator may simultaneously be the means for obtaining indications as to the distance traveled in the said direction if the revolutions. of the integrator are counted. In connection with the present invention, integrators of any suitable type may be used; it is considered preferable, however, to employ integrators such as claimed in the above-mentioned parent application,

An embodiment of the stabilized and directed platform is illustrated in Figs. 2 and 3. Ihe platform proper 31 is carried by a Cardan structure comprising a base-plate 30, two supports 3l and two gimbal rings 32 and 33. Ring 32 is rotatable about axis 34, and ring 33 about axis 35. 36 is a shaft which supports platform 31, and its axis is arranged at right angles to axis 35 and normally at right angles to 34. A protective cover 38 for the instruments mounted on the platform is attached thereto by suitable means, for instance by screws 39. Means are provided for stabilizing platform 31. For this purpose gyros 40 and 4I are mounted thereon. In a preferred embodiment, these stabilizing gyros 40 and 4| are designed as synchronous motors as shown in Figs. 4 and 23. The gyros are capable of precessing on shafts 42 and 43 respectively. Their impulse shafts 44 and 45 respectively are arranged at right angles to each other, and, if the platform is to be directed north-south, the impulse shafts are preferably parallel and at right angles respectively to the meridian.

In order to maintain platform 31 in a definite direction, and more particularly to maintain it in the north-south direction as will be desirable in most instances, a compass gyro 46 and an aximuth gyro 50 are also mounted on platform 31. Compass gyro 46 has three degrees of freedom, determined by the axis of precession 41, Cardan shaft 48, and impulse shaft 49, the latter being parallel to the meridian when the apparatus is working properly. In the example of Fig. 2, impulse shaft 44 of the one stabilizing gyro 4|) is parallel to the impulse shaft 49 of the compass gyro. This is the preferred arrangement; however, other arrangements of the axes in relation to each other may be employed. Azimuth gyro 5U has a horizontal precession axis 5|. Its impulse axis 52 may be either horizontal as shown. In this arrangement, the azimuth gyro is the means for turning the platform into the desired direction, and the compass gyro is the means for controlling the azimuth gyro.

Although the stabilizing gyros 40, 4I on the one hand, and the compass gyro 46 and the azimuth gyro 50 on the other hand are the means proper for stabilizing and directing respectively platform 31, they would not be capable of functioning satisfactorily over a considerable length of time unless means are provided for eliminating or neutralizing or correcting certain external and internal influences. Such external inuences are caused by the apparent and by the true rotation of the earth, and internal influences are caused by the bearing friction. The apparent rotation of the earth is to be compensated at the stabilizing gyros and the compass gyro proportionally to the components of the crafts speed in the directions of the impulse axes of the gyros. The inuence of the true rotation of the earth is to be corrected at the stabilizing gyros and at the aximuth gyro depending upon the geographical latitude. If, however, the impulse axes of the stabilizing gyros are directed north-south and east-West respectively as in the illustrated example, no correction in this respect, that is to say, in respect to the true rotation of the earth, is required at the north-south stabilizing gyro. The internal influences which have to be taken in consideration consist mainly of the bearing friction exerting precession moments at the gyros.

'I'he means for effecting corrections with reference to the apparent rotation of the earth or, what is equivalent thereto, to the speed of the craft, may be controlled either by hand if in each instance the speed is known from other sources, or they may be controlled by a device automatically finding the speed of the craft over ground. Such speed-finding devices may be mounted on the same platform with the gyros 40, 4|, 46 and 50. In other words, certain correcting forces may be derived from the same devices which are to be stabilized and directed, and which for this purpose are mounted on the platform in order to allow speed, distance travelled, and location of the craft to be read oif accurately on the indicating instruments actuated by said devices. A

For this reason, integrators 53 and 54 are preferably arranged on platform 31 in such a manner that integrator 53 is associated with stabilizing gyro 40, and that integrator 54 is associated with stabilizing gyro 4|. Any suitable 75 type of integrators as defined above may be used. It is, therefore, by way of example only that there is described hereinafter the use of integrators of the type cl'aimed in the parent Patent 2,109,283, February 22, 1938. The gyros are so arranged with respectto each other that the impulse shaft of either stabilizing gyro is parallel to the direction of acceleration forces to which its associated integrator or the oscillatable body therein responds. The relative position of the integrators is also determined by the fact that the lines tangent to the circles described by the oscillatable bodies through the points of intersection of the oscillation circles with the radii corresponding to the center positions of the oscillatable bodies are at right angles to each other, no matter whether the oscillatable bodies have vertical or horizontal axes of oscillation. If, as in the example described, the axes of oscillation are maintained in a vertical position, not only said tangents but also said radii will be at right angles to each other.

From the foregoing it is apparent that the impulse axes of the compass gyro 46, of the azimuth gyro 50 and of the stabilizing gyro 40 as well as the direction of the accelerations to which integrator 53 responds, are normally parallel with each other and directed north-south. For this reason, stabilizing gyro and integrator 53 are designated as the north-south stabilizing gyro and as the north-south integrator respectively. In an analogous manner, stabilizing gyro 4| and integrator 54 which operate in a direction at right angles to the rst-mentioned direction, are denoted as the east-west stabilizing gyro and as the east-west integrator respectively.

The means for controlling corrections in consideration of the true rotation of the earth are not necessarily mounted on the stabilized platform, and will, therefore, be described in another connection.

In order to eliminate the effects of bearing friction, there are provided on the platform 31 two shaking devices 55 and 56 the axes of which are at 90 to each other. The shaking devices which will be described in detail below, are connected with the platform and mounted thereon so that they will act upon the platform directly. The shaft of the shaking device 55 is parallel to the impulse shaft 44 of the stabilizing gyro 40 and the shaft of the shaking device 56 is parallel to the impulse shaft of the stabilizing gyro 4|. A third shaking device 51, 58 (see Fig. 20) consists of two parts one of which is arranged on the upper end of shaft 36 and the other on the lower end. These parts are covered by the protective hoods 264 and 265 which are fastened to Cardan ring 33 in a suitable manner, as for example, by screws 266 and 261 respectively. Instead of providing shaking devices such as and 56 on the platform, shaking devices of the type shown in connection with shaft 36 may be mounted on the shafts 34 and 35. On shaft 34, slip rings 60 are fastened of which but a few are indicated and whose function it is to tap current from the various electric conductors indicated in Figs. 1 and 23-28. Corresponding slip ring leads (not shown in the drawings) are provided on the other shafts also for the purpose of passing the current from ring 32 via ring 33 to platform 31. As these devices are well known and not mentioned in the claims, they are omitted. from the drawings for sake of clearness.

The various instruments which are mounted on the platform will now be described in detail.

Since stabilizing gyros 40 and 4| are alike so far as their main parts are concerned, a description of the east-west gyro 4| illustrated in Fig. 4 will be sufficient for the understanding of their structure. Gyro 4| is designed as a socalled float gyro in order to diminish the friction. There is no reason, however, why a gyro of some other well-known type might not be applied successfully. An external case 6| rigidly fixed to platform 31 is lled with a liquid 62 on which a float 63 is carried. The float has a vertical shaft with axis 43 which simultaneously is the precession axis of the gyro contained in the float. 64 is the gyro body with impulse shaft 45. The gyro box 65 is rigidly connected with oat 63 by means of bracket 66. On the top of float box 6| a junction box 68 is arranged into which the upper end 69 of the float shaft protrudes, and which is rigidly connected with the said float box by brackets 61. 'I'he shaft is journalled at its upper and lower ends in bearings 10 and 1| respectively.

Means are provided for compensating the influence of the rotation of the earth on the stabilizing gyros 40 and 4|, special means being available at the east-west gyro to compensate for both the true and the apparent rotation of the earth. The north-south gyro 40 is only provided with means for compensating the apparent rotation of the earth. The said compensating means are housed in junction box 68; they are shown upon a large scale in Figs. 5 and 6 with respect to the above-mentioned east-west gyro 4|, and in Figs. 7 and 8 as regards the north-south gyro 40.

As stated above, the extension 69 of precession axis 43 protrudes into junction box 68 (Figs. 5 and 6). Said axis or spindle carries on its end a rigidly connected yoke-shaped piece 12, the arms 13 and 14 of which can be seen in Fig. 6 where the middle portion is not shown. Each of the arms 13 and 14 has at its end a freely rotating pulley 15 and 16 respectively.

In addition the box 68 contains two synchronous receivers 11 and 18 one arranged higher than the other; receiver 11 acts upon a shaft 19 and receiver 18 on a shaft 80. Shafts 19 and 80 are arranged between brackets |03 and |04 xed on box 68, and the receiver 11 is tted to the bracket |05. The axes of shafts 19 and 80 are at right angles to the zero position of the yokeshaped piece 12 which position is determined by the direction of arms 13 and 14 when the gyro 4| is not precessing. Moreover, the two sectors 8| and 82 which are capable of oscillating about shafts 85 and 86 are pivoted to the case 68 at 83 and 84 respectively. The sectors carry, on shafts 81 and 88, the rotatable levers 9| and 92 which are balanced by weights 89 and 90. The ends of the levers carry pulleys 93 and 94 which are connected by suitable driving means, such as cords 95 and 96 with the pulleys 15 and 16 respectively.

Spiral springs 91 and 98 arranged on the shafts 81 and 88 as well as on levers 9| and 92 serve to maintain the cord drives under a definite tension. Each of the receiver shafts 19 and 80 carries a worm 99 and |00 respectively which mesh with corresponding Worm teeth |0I and |02 respectively on the segments 8| and 82. The receiver 11 may be adjusted by a transmitter 460 (see Figs. 21, 23, 25) in proportion to the ground speed component, in the manner described below, the said component being parallel to the impulse shaft 45 of gyro 4|. The said receiver serves to compensate for the influence produced by the apparent rotation of the earth due to the ground speed of the craft.

A transmitter 300 (see Figs. 12, 13, 23, 2'1) may act upon t'he receiver 18. The said receiver serves for compensating the influence produced by the true rotation of the earth upon the east-west gyro 4|. Transmitter 300 may be operated to act upon receiver 18 in proportion to the cosine of the geographical latitude as will be described below.

As mentioned above, the north-south stabilizing gyro 40 requires only a device for compensating the apparent rotation of the earth. The parts serving this purpose are the same as those used for gyro 4| and are represented in Figs. '1 and 8 and have the same reference numerals, except for the addition of a prime, as the corresponding parts illustrated in Figs. and 6. It should be noted that the free arm 14' of the yoke-shaped piece 12 may serve to balance the mass of arm 13. Receiver 11 is set by transmitter 451 (see Figs. 21, 23, 25) in proportion to the speed component which lies parallel to the impulse shaft 44 of gyro 40.

The compass gyro 46 with north-south impulse shaft 49 is shown in Fig. 9. This gyro may be of any suitable type. In order, however, to reduce the friction to a minimum, it is preferable to employ a gyro of the float type. For this purpose, a case |06 lled with a liquid and provided with a float |09 is secured to platform 31 by suitable means, such as screws |08.

Float |09 is journaled in an upper bearing H0 and a lower bearing in case |06. It can swing about a vertical shaft 41, and within its interior, supports a frame H2. Frame H2 has a horizontal axis which lies above the impulse shaft 49 of the gyro, and is dened by journals H3 and H4 with the result that frame H2 may oscillate in iloat |09. Shaft 41 is rigidly connected with float |09. Journals H3 and H4 are likewise rigidly secured to frame H2, and are connected with shaking devices |43 and |44 which will be described below. Gyro box |5 has a vertical shaft H6, |1 offset laterally by a predetermined amount in relation to shaft 41 and to impulse shaft 49. Shaft H6, H1 is journaled in frame H2 at points H8 and H9 in such a manner that the center of gravity of the whole system lies in a plane containing the axis of shaft 41 when the gyro is not precessing. The oscillations which gyro box H5 can perform about the axis of shaft H6, H1 act upon a spring |20 fastened to the gyro box H5 and the frame H2. This arrangement has been chosen in order to cause the gyro to precess, under the action of horizontal accelerations, in a plane having a definite inclination to the horizon, rather than in a horizontal plane.

A contact arm |2| is connected to journal H4 of frame H2 so as to swing together therewith and to slide over a contact segment |22 fixed to flott body |09. Segment |22 carries a contact |23 so arranged, as shown in Fig. 10, that arm I2. engages contact |23 only when frame H2 is in its center position, that is to say when the axes of shafts 41 and H6, H1 are parallel with each other. 'I'he switch formed by parts |2| and |23 is connected in series with another switching device one element of which, that is to say a contact arm |24, is carried by the upper end of the vertical float shaft 41. Contact arm |24 is capable of sliding over contacts |26 and |21 which are fixed on the case (see Figs. a). The said contacts are provided on either side of the center position of contact arm |24, and a current supply is interrupted yby an insulating piece |28 when the contact arm is in its center or neutral position. Since the two contact devices |2| and |23 as well as |26 and |21 are connected in series (see Fig. 23) current can flow only when the contact arm |2| is in its center position and at the same time arm |24 is off its center or neutral position.

As shown in the drawings, contact arm |24 is not directly connected to shaft 41 but arranged on a yoke-shaped piece 613 which, in turn, is fixed on shaft 41. The yoke-shaped piece 613 is part of a device intended to compensate the apparent earth rotation, as described above and illustrated in Figs. 7 and 8. 'I'here is no need, therefore, of giving a description of the individual parts which co-operate here with receiver 611 in place of receiver 11 (Figs. 7 and 8) of the north-south stabilizing gyro 40. The said compensating device is housed in case 668 supported by brackets 661 on case |06. At the bottom of box 668, there are arranged the contacts |26, |21 and the insulating piece |28, and in the cover of the box an opening 669, preferably of circular form, is provided for a purpose to be referred to below. The receiver 611 is controlled by the same transmitter 451 that is also employed to actuate the receiver 11'.

Means are provided to brake the rotation of the float |09 about the axis of shaft 41. For this purpose, the aforementioned yoke-shaped piece 613 has an extension |29 with an arm |30 pointing upwards. The said arm projects through the said opening 669 in box 668 and with its end extends into a hole |3| of a copper disc |32 which has a vertical rotatable shaft |33 connected to it. Said shaft is journaled, as described below, in the shaking devices |34 and |35 which are attached to the bracket |36 connected with the case |06. The copper disc is part of an eddy-current brake, the brake magnet |31 of which as well as the coil or winding |38 are also supported by bracket |36. A horizontally swinging body |39 is arranged coaxially with the copper disc |32, the mass of said swinging body being on that side of shaft H6, H1, which is opposite to the side on which the mass of the gyro body |40 with gyro box |5 is situated. The horizontally swinging body |39 is provided with an arm arranged on the opposite side of its axis of oscillation by which it is resiliently coupled over spring |42 with copper disc |32. The said spring should be given a small initial tension. Body |39 may be mounted so as to rotate freely on shaft |33 of copper disc |32.

Fig. l1 shows the azimuth gyro 50 with its precession axis 5| and impulse shaft 52. The azimuth gyro, in its case |45, is mounted to rotate in a frame connected with platform 31, say by screws |68, and may carry, in a case |46 arranged on frame |69, a device to balance the influence of the true rotation of the earth, similar to the one contained in the case 68 of the stabilizing gyro 4| (Figs. 5 and 6). The azimuth gyro 50, however, has no device to balance the apparent rotation of the earth. Receiver 18 of the azimuth gyro (see Fig. 23) which corresponds to receiver 18 of the stabilizing gyro 4| in Fig. 6, is set by a transmitter 30| which may be turned by hand simultaneously with transmitter 300. The adjustment of receiver 18', effected by transmitter 30|, is not proportional to the cosine but to the sine of the geographical latitude. The de- 

